Disintegrator for fibrous materials



Patented Apr. 13, 1954 UNITED STATES r TNT OFFICE Sweden ApplicationJanuary 27, 1951, Serial No. 208,190

'7 Claims. (Cl. 92--23) The present invention refers to an apparatus fordisintegrating and fibrating of fibrous materials such as pulp bundles,paper waste and the like in water. Apparatus of this description,socalled. pulp disintegrators, principally consist of a rotor servingfor the circulation and the working of the pulp, a pump in the form of arotating pump wheel, and a strainer plate arranged above the outlet fromthe pulp container, through which strainer plate the disintegrated pulpis sucked out and strained.

The present invention has for its object to increase the disintegratingcapacity and the working capacity of such pulp disintegrators, and isprincipally distinguished by the feature that the rotor, the pump wheel,and the strainer plate are built together to form a rotating unit. Here,the vanes serving for the circulation and the working of the pulp arepreferably arranged on the hub portion of'th'e rotor, while thepumpwheel has a concentricallyarranged axial inlet around the hub portion,said inlet being covered by an annular strainer plate. Thisconstructively simple arrangementof said parts relatively to each otherbrings the advantage that the strainer plate rotates, merging closely tothe vanes, so as to attain, in consequence thereof, a powerfullydisintegrating effect on the material.

The invention will be described more closely with reference to theaccompanying drawings,

' which illustrate a form of embodiment of a pulp disintegratorconstructed in accordance with the invention. Fig. 1 represents avertical section and Fig. 2 a plan view of the pulp disintegrator. Fig.3 shows a section through a portion of the strainer plate, representinga special embodiment of the same.

The rotor l is arranged at the bottom of a receptacle 2, which isintended to be filled with the material to be disintegrated and withwater in a proportion of, for instance, 3.5 to of pulp. Arranged in thehub portion of the rotor are a number of vanes 3 adapted to bring thepulp into rotation within the container while working at the same timeupon the pulp and facilitating the disintegration thereof. The bottom ofthe container is inclined and consequently brings about a verticalcirculation of the pulp, guide plates 4 arranged on the cylindrical wallof the container then efiecting a deflection of the stream of pulpinwardly toward the centre of the container, where the pulp is thuscaused to fiow downwardly. Extending from the rotor hub is a plane disk5 forming an attachment for a number of pump wheel vanes 6, which aredisposed in an ll surrounding the rotor, said pump housing being securedin a flange 12 on the pulp container, the portion of the pump housingsituated between the pump wheel and said flange then forming an annularpart of the bottom of the container. The strainer plate 1 is securedwith its inner edge in the hub portion of the rotor, and is attachedwith its outer edge to the wall 8, which at the same time tightens thepump wheel against the pump housing. The plate,

which may be plane or conical, is also supported by the vanes 6, towhich it is preferably also secured. Screwed onto the part of the pumphousing I! located on a level with the bottom of the container is ascraper I3 extending over the strainer plate and preventing the fibrouspulp from sticking to the plate.

The bottom portion M of the pump housing is tightened against the rotorshaft [6 by a stuffing box l5, and is formed as an attachment for abearing housing I! arranged underneath the pump housing, said bearinghousing I! having the shaft I6 mounted therein. The rotor shaft Itcarries at its lower end a belt pulley 18, through which the rotor isconnected to a driving motor, not shown in the drawing. The pulpcontainer is mounted on a number of posts 19, the rotor with itsassociated bearing housing being suspended in the pump housing I!attached to the bottom of the container.

The number of revolutions of the rotor is chosen difierently withrespect to the nature of the material to be treated. For example, thenumber of revolutions may vary from 300 up to 800 revolutions perminute. When the vanes 3 throw the mixture of Water and pulp over thestrainer plate 1, the liberated fibres will be separated to pass throughthe holes of the strainer plate and to be caught by the vanes 6, 9, themixture of fibres and water being thus hurled out into the channel H3 inthe pump housing, whence it is emptied into a collecting receptacle, oris returned to the pulp container 2 to be subjected to repeatedtreatment. Through the arrange This outlet opens in front ment of thestrainer plate 7 immediately outside the vanes 3, and through the rotarymovement of the strainer plate, the latter will powerfully act upon thepulp of fibres in order thus to actuate the disintegration of the fibresin a favourable way. This effect may be further increased by making thestrainer plate in the manner shown in Fig. 3. The strainer plate isprovided on the upper side thereof with recesses or depressions arrangedaround the holes 29, the bottom portions of said recesses or depressionsforming oblique surface 28 inclined to the walls of the holes. Ifdesired, the strainer plate may instead be channeled in a radialdirection. The holes themselves may be either cylindrical or conical,and in the latter case they widen to the lower side.

On account of the rotary movement of the strainer plate, the latterkeeps purer than is the case in known constructions, where the straineris stationary and a rotating scraper must be used to keep the plateclean. In an arrangement according to the present invention, no scraperis normally required, a scraper being made use of only in cases more orless severe.

The disintegrating and working capacity of the apparatus may beincreased further by making the pulp container of a polygonalconfiguration, for instance with 12 sides, instead of making it round,the material being then also worked upon by the walls of the containerduring the rotary movement of the pulp.

I claim:

1. A pulp beater comprising a pulp container, a rotary impeller mountedin said container at the bottom thereof, said bottom having a circularoutlet opening coaxially surrounding the impeller, a ring-shapedstrainer plate covering said outlet opening and mounted to rotatetogether with the impeller, and a centrifugal pump wheel mountedcoaxially with the impeller below said strainer plate and having anaxial inlet registering with said outlet opening.

2. A pulp beater as claimed in claim 1, wherein the impeller has a hubportion carrying beating and circulating vanes at the top thereof andvanes of the pump wheel at its peripheral portion beneath the strainerplate.

3. A pulp beater as claimed in claim 1, wherein the strainer plate issupported by the vanes of the pump wheel.

4. A pulp beater comprising a pulp container, a rotary impellercentrally mounted in said container at the bottom thereof and providedwith a central hub portion carrying beating and circulating vanes, acentrifugal pump wheel forming a peripheral portion of the impeller,said peripheral portion having a circular discharge opening, aring-shaped strainer plate covering said discharge opening and mountedon the peripheral portion of the impeller outside said heating andcirculating vanes, and pump wheel vanes provided in said dischargeopening below the strainer plate.

5. A pulp beater as claimed in claim 4, wherein the impeller isrotatably mounted in a pump housing secured to the bottom of the pulpcontainer and containing an outlet channel communicating with thedischarge opening of the impeller.

6. A pulp beater as claimed in claim 4, wherein the impeller and thestrainer plate form a central rotary part of the bottom of the pulpcontainer.

7. A pulp beater as claimed in claim 4, wherein the strainer plate isprovided on the upper side thereof with recesses or depressions arrangedaround the holes in the plate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 34,581 Lyman Mar. 4, 1862 2,351,728 Wells June 20, 19442,557,174 Cowles June 19, 1951 FOREIGN PATENTS Number Country Date564,554 Germany Nov. 19, 1932

